This invention relates to an arm assembly for a chair, and more particularly to an arm assembly including a feature providing adjustment in the height of the armrest relative to the seat of the chair.
Adjustable height armrest assemblies are known, and examples are illustrated in various prior art patents. In general, many adjustable height armrest assemblies include a support member interconnected with the seat or base of the chair and extending upwardly from the seat adjacent a side of the seat, and an armrest assembly slidably mounted to the support member. The armrest assembly typically includes an armrest member and a depending tubular member defining an internal passage within which the support member is slidably received. The tubular member telescopes relative to the support member to adjust the height of the armrest relative to the seat. A movable latch member is interconnected with the armrest assembly, and is selectively engageable with one of a series of spaced notches or the like formed in or on the support member. In some versions, the latch member includes a manually engageable trigger section which selectively moves the latch member into or out of engagement with the notches. In other versions, the latch member is internal and is engageable with an actuator arrangement for selectively moving the latch member between an engaged position and a disengaged position, depending upon the position of the armrest member relative to the support member.
It is an object of the present invention to provide an arm assembly for a chair which includes a latch member having an external trigger section for moving the latch member between an engaged position and a disengaged position. It is a further object of the invention to provide such an arm assembly which provides an improved arrangement for pivotably mounting the latch member relative to the support member. Yet another object of the invention is to provide such an arm assembly in which the armrest member is pivotable about a substantially vertical pivot axis, for adjusting the position of the armrest member in a horizontal plane. A still further object of the invention is to provide such an arm assembly having an arrangement which provides the dual function of pivotably mounting the latch member for movement between its engaged position and its disengaged position, and pivotably mounting the armrest member for movement about a substantially vertical pivot axis. Yet another object of the invention is to provide an arm assembly with an improved construction for releasably maintaining the armrest member in a selected horizontal position relative to the support member to which the armrest member is mounted. Yet another object of the invention is to provide an adjustable height armrest assembly which includes a retainer arrangement for preventing the armrest assembly from being disengaged from the support member, to which the armrest assembly is mounted for telescoping movement. Yet another object of the invention is to provide such an arm assembly having an improved construction for the latch member and its associated trigger and spring, which functions to bias the latch member toward its engaged position.
In accordance with the invention, an arm assembly for a chair having a seat and a back includes a support member which extends upwardly from the seat adjacent a side of the seat. An armrest assembly includes an armrest member and a depending tubular member which defines an internal passage within which the support member is received, for providing telescoping movement of the armrest assembly relative to the support member. The tubular member includes a series of spaced engagement areas or notches. The latch member includes an upper trigger section and a lower engagement section which is selectively engageable with the spaced engagement areas of the support member, for selectively fixing the height of the armrest member relative to the seat. The latch member is preferably mounted to the armrest assembly for pivoting movement between an engaged position in which the engagement section is engaged with one of the notches, and a disengaged position in which the engagement section is moved out of engagement with the notches. The latch member is preferably biased toward its engaged position.
The tubular member defines an upper end to which the armrest member is mounted by means of a cap member secured to the upper end of the tubular member. The cap member provides the dual function of pivotably mounting the latch member to the tubular member, and pivotably mounting the armrest member to the tubular member for movement about a substantially vertical pivot axis. The latch member includes transverse pin structure which is received within one or more arcuate recesses or seats associated with the tubular member. The cap member includes one or more mating arcuate recesses or seats which engage the pin member when the cap member is secured to the upper end of the tubular member, and the arcuate recesses or seats cooperate to pivotably mount the latch member to the tubular member. In addition, a pivotable mounting arrangement is interposed between the armrest member and the cap member for pivotably mounting the armrest member to the cap member. The pivotable mounting arrangement includes a pivot member, such as a threaded fastener, which is engaged with the armrest member and received within a passage defined by the cap member.
A detent arrangement interposed between the armrest member and the cap member for selectively maintaining the armrest member in a predetermined horizontal position relative to the tubular member. A series of laterally facing detent areas are provided on the cap member, and a resilient engagement member is mounted to the armrest member. The engagement member is selectively engageable with one of the laterally facing detent areas for releasably maintaining the armrest member in a predetermined horizontal position relative to the tubular member. The resilient engagement member may be in the form of a spring member having a pair of ends which are fixedly mounted to the armrest member, with an engagement area located between the spaced ends of the spring member. The spring member deflects as the engagement area moves between the laterally facing engagement areas, and moves the engagement area of the spring member into one of the laterally spaced detent areas when the engagement area of the spring member is aligned therewith, so as to releasably maintain the armrest member in position.
A retainer arrangement is interposed between the armrest assembly and the support member for maintaining the armrest assembly in engagement with the support member. The retainer arrangement includes a retainer member engaged with the support member and engagement structure provided on the latch member. The engagement structure is engageable with the retainer member when the tubular member is moved to a predetermined extended position relative to the support member. The support member defines a channel within which the series of spaced engagement areas are located. An engagement section of the latch member is received within the channel, and at least a portion of the retainer member overlies the channel for engagement with the engagement section of the latch member when the arm assembly is raised relative to the support member, to prevent disengagement of the arm assembly from the support member.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.